What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 103675-5: Phosphorylated tau 181 IA (P) [Mass/Vol]

Name: LOINC Code 103675-5: Phosphorylated tau 181 IA (P) [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:18.498Z

103675-5 is a LOINC code used to identify Phosphorylated tau 181 IA (P) [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tau protein.phosphorylated 181. It is commonly used with the system or sample type Plas.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tau protein.phosphorylated 181. It is commonly used with the system or sample type Plas.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Both
Method: IA

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Phosphorylated tau 181 [Mass/volume] in Plasma by Immunoassay
Tau protein.phosphorylated 181
181P; Alzheimer disease; Alzheimer's disease; Chemistry; EIA; ELFA; ELISA; Enzyme immunoassay; IAA; Level; Mass concentration; MEIA; phospho T181; Pl; Plasma; Plsm; Point in time; PR; Prot; p-tau181; pThr181; QNT; Quan; Quant; Quantitative; Random; SUDS; Thr181; threonine 181

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Phosphorylated tau 181 IA (P) [Mass/Vol]Phosphorylated tau 181 [Mass/volume] in Plasma by Immunoassayp-tau181 Plas IA-mCncTau protein.phosphorylated 181CHEMPhosphorylated tau 181, BloodMCnc

Frequently asked questions

Code details

Code103675-5

SystemLOINC

Display namePhosphorylated tau 181 IA (P) [Mass/Vol]

DescriptionTau protein.phosphorylated 181

Short namep-tau181 Plas IA-mCnc

ComponentTau protein.phosphorylated 181

PropertyMCnc

TimingPt

System (specimen)Plas

ScaleQn

MethodIA

ClassCHEM

Example unitspg/mL

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.77

Last changed2.77

Consumer names

Phosphorylated tau 181, Blood

Part names

Tau protein.phosphorylated 181MCncPtPlasQnIAPhosphorylated tau 181Mass ConcentrationPoint in time (spot)PlasmaImmunoassay

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.